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LAS基因对于植物侧生分生组织有重要影响。它被证实在拟南芥、番茄等草本科植物营养生长阶段参与腋生分生组织的形成,但在木本植物中的基因功能尚缺乏深入研究。本研究以沙柳为材料,利用RT-PCR技术成功克隆沙柳LAS基因,命名为SpsLAS,并对其进行生物信息学分析。结果表明,该基因CDS序列全长1 320 bp,编码439个氨基酸,预测蛋白分子量为49.876 8 k D,理论等电点(PI)为6.66,是亲水性蛋白;同源氨基酸序列比对结果表明沙柳LAS基因与番茄LS、拟南芥LAS等功能已确认的LS亚家族基因同源性较高,氨基酸相似性达50%以上;系统进化分析表明SpsLAS与杞柳和毛果杨亲缘关系更近;对LAS进行功能结构域分析得知LAS基因具有GRAS基因家族典型特征,属于GRAS基因家族LS亚家族;预测未发现跨膜结构和信号肽区域;SpsLAS蛋白二级结构包含173个α螺旋(Alpha helix),72个延伸链(Extended strand),194个无规则卷曲结构(Random coil);亚细胞定位预测该基因很可能定位于细胞核内。沙柳LAS基因的克隆对于研究木本植物萌蘖及其分枝机制有重要意义,同时丰富了木本植物中GRAS基因家族的相关研究。
LAS gene has important effect on plant lateral meristem. It has been shown that axillary meristems are involved in the vegetative growth of herbaceous plants such as Arabidopsis thaliana and tomato. However, the gene function in woody plants is lack of further study. In this study, Salix psammophila was used as material, and the LAS gene of Salix psammophila was successfully cloned by RT-PCR. The LAS gene was named as SpsLAS, and its bioinformatics analysis was carried out. The results showed that the CDS sequence of this gene was 1 320 bp in length and encoded a protein of 439 amino acids. The predicted molecular weight of the CDS was 49.876 8 kD and the theoretical isoelectric point (PI) was 6.66, which was a hydrophilic protein. The homologous amino acid sequence alignment The results showed that the SalI gene Lus was highly homologous to the identified LS subfamily genes of LS and LAS in Arabidopsis thaliana and the amino acid similarity was more than 50%. Phylogenetic analysis showed that the genetic relationship between Salvia miltiorrhiza L The functional domain analysis of LAS revealed that LAS gene has the typical GRAS gene family and belongs to the LS subfamily of GRAS gene family; no transmembrane structure and signal peptide region are predicted; the secondary structure of SpsLAS protein contains 173 α-helix Alpha helix, 72 extended strands and 194 random coils. The subcellular localization of this gene predicted that the gene might be localized in the nucleus. The cloning of LAS gene in Salix psammophila plays an important role in studying the sprout and its branching mechanism of woody plants, and at the same time enriching the GRAS gene family in woody plants.